JP2002047473A - Adhesive and method for bonding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for bonding which can bond a matter to an addition-cured silicone rubber cured product, and a silicone rubber molded item formed by bonding a silicone rubber layer or an adherend to a silicone cured product containing a platinum catalyst. SOLUTION: The method for bonding is such that, on the surface of a silicone rubber cured product containing a platinum catalyst, an adhesive composition comprising a first component of a polyorganosiloxane which has vinyl groups bonded to silicon atoms in the molecule, is substantially linear and has a viscosity of 10-8,000,000 cps, and a second component of a polyorganohydrogensiloxane which has at the terminal at least one hydrogen atom bonded to more than two silicon atoms on an average in the molecule, is placed in a thickness of 0.001-10 mm, contact-bonded, and then allowed to stand at room temperature (20-30 deg.C) or heated to 30 deg.C or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method, and more particularly to a method for bonding a silicone rubber layer to a cured silicone rubber containing a platinum catalyst, and a method for curing a silicone rubber containing a platinum catalyst using the bonding method. The present invention relates to a bonding method for bonding an object and an adherend such as glass, plastic, metal, wood, carbon or the like via a silicone rubber layer.

[0002]

2. Description of the Related Art Conventionally, addition-curable adhesive liquid silicone rubber and condensation-curable adhesive liquid silicone rubber have been widely used as silicone rubber-based adhesives in a wide variety of applications such as architectural use, electric / electronic parts, and automobile parts. Have been.

[0003]

It is a general method to develop a desired adhesive force while curing these adhesive liquid silicone rubbers by heating or long-term curing at room temperature. Even when an addition-curable adhesive liquid silicone rubber or a condensation-curable adhesive liquid silicone rubber was used, a sufficient adhesive strength could not be obtained.

[0004] In general, addition-curable silicone rubber is no longer reactive once it has been cured. Therefore, addition-curable silicone rubber must be cured to further adhere to the adherend with the cured addition-curable silicone rubber. It is necessary to modify the surface of the object, and this has a problem that labor and cost increase.

[0005] In addition, when the addition-curable silicone rubber cured product is damaged, the damaged portion cannot be repaired. Therefore, there is a problem that the entire silicone rubber molded product must be replaced with a new one.

The present invention has been made to solve the above-mentioned conventional problems. That is, the present invention relates to an adhesion method capable of adhering to an addition-curable silicone rubber cured product, that is, a silicone rubber cured product containing a platinum-based catalyst, and a silicone rubber layer formed on a silicone rubber cured product containing a platinum-based catalyst. To provide a molded silicone rubber product to which an adherend is adhered.

[0007]

According to the present invention, there is provided a bonding method comprising, as a first component, a vinyl group bonded to a silicon atom in a molecule on a surface of a first layer made of a cured silicone containing a platinum-based catalyst. Substantially linear, having a viscosity of 10-8,
A polyorganosiloxane having a molecular weight of more than 2,000,000 cp, and a polyorganohydrogensiloxane having, as a second component, at least one hydrogen atom at the terminal having an average of more than two hydrogen atoms bonded to a silicon atom in the molecule. Applying the adhesive composition to a thickness of 0.001 to 20 mm to form a second layer, leaving the composition in an environment of 20 ° C to 30 ° C or heating to 30 ° C or more to cure the second layer. And adhering to the first layer.

In another bonding method of the present invention, a first layer made of a cured silicone material containing a platinum-based catalyst is coated on the surface of a first layer.
As a component, it is substantially linear and has a viscosity of 10 to 8,000, having a vinyl group bonded to a silicon atom in the molecule.
An adhesive comprising a polyorganosiloxane having a molecular weight of 000 cp and a polyorganohydrogensiloxane having, as a second component, at least one hydrogen atom having an average of more than two hydrogen atoms bonded to silicon atoms in a molecule at a terminal thereof. Applying the composition to a thickness of 0.001 to 20 mm, the second
Forming a layer, and laminating a third layer formed of a material selected from the group consisting of glass, plastic, metal, wood, and carbon on the second layer;
Leaving in an environment of 20 ° C. to 30 ° C. or heating to 30 ° C. or more to cure the second layer and bond the second layer to the first layer.

In the above-mentioned bonding method, examples of the adhesive include those comprising the following composition.

That is, the composition is, as the first component, a substantially linear polyorganosiloxane having a vinyl group bonded to a silicon atom in the molecule and having a viscosity of 10 to 8,000,000 cp. And an adhesive composition comprising, as the second component, a polyorganohydrogensiloxane characterized in that the second component has at least one hydrogen atom at the terminal exceeding an average of two hydrogen atoms bonded to a silicon atom. .

[0011] In the bonding method of the present invention, the following components are provided on the surface of a cured silicone rubber containing a platinum-based catalyst;
A substantially linear polyorganosiloxane having a vinyl group bonded to a silicon atom in the molecule and having a viscosity of 10 to 8,000,000 cp;
After applying an adhesive comprising a composition containing a polyorganohydrogensiloxane characterized in that the component has at least one hydrogen atom at the terminal exceeding an average of more than two hydrogen atoms bonded to silicon atoms, room temperature (20 ° C.) -30 ° C) to cure. Or you may heat up to 30 degreeC or more.

For this reason, it has become possible to adhere to an addition-curable silicone cured product which has been recognized as being impossible in the past. According to the method of the present invention, only an adhesive putty may be adhered to an addition-curable silicone rubber cured product, that is, a cured silicone rubber containing a platinum-based catalyst, and further, glass, plastic, metal, wood Alternatively, an adherend such as carbon or the like may be placed and bonded.

[0013] The bonding mechanism according to the method of the present invention is considered to be performed as follows.

By disposing an adhesive on a silicone rubber cured product containing a platinum catalyst, the platinum-based catalyst in the cured product also acts on the adhesive putty, so that the adhesive is cured while adhering to the silicone rubber cured product. Think that you do.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a bonding method according to an embodiment of the present invention will be described.

1 used in the adhesive putty used in the present invention
The component vinyl group-containing polyorganosiloxane is a component serving as a base polymer of the polyorganosiloxane composition used in the present invention.

The first component is crosslinked by an addition reaction to form a network molecule. To form an elastic adhesive layer, the first component has two or more vinyl groups bonded to silicon atoms in one molecule, and the plastic adhesive layer has When it is formed, it has one or more vinyl groups per molecule and less than two on average.

Unless a low hardness is required, the first
As the component, the former which absorbs stress by forming an elastic adhesive layer having excellent mechanical strength utilizing characteristics of silicone rubber is preferable.

The siloxane skeleton of the first component is substantially linear, and may have some branches or a three-dimensional structure. The viscosity of the first component, that is, the number of siloxane units is 1
0 to 8,000,000 cp, preferably 100
Up to 10,000 cp, more preferably 500 to 8.0
The range is 00 cp.

If the viscosity is less than 10 cp, the composition will become tacky or fluid, resulting in poor workability as an adhesive. On the other hand, those having a viscosity exceeding 8,000,000 cp are not only difficult to synthesize, but also difficult to mix fillers and the like.

The organic group other than the vinyl group bonded to the silicon atom of the first component includes a linear or branched alkyl group such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl and dodecyl. Cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, tolyl and xylyl; aralkyl groups such as 2-phenylethyl and 2-phenylpropyl; chloromethyl, chlorophenyl and 3,3,3-trifluoropropyl Examples thereof include a monovalent substituted hydrocarbon group.

Of these, 92 mol% or more is preferably a methyl group, and substantially all of the methyl group is used, since the advantages of the silicone adhesive such as heat resistance, cold resistance, and weather resistance can be sufficiently exhibited. Good. Other groups such as a phenyl group when cold resistance is required for the adhesive and a 3,3,3-trifluoropropyl group when oil resistance is required can be used in combination according to required characteristics.

The molecular chain terminal of the first component is preferably a triorganosiloxane unit in which only a substituted or unsubstituted monovalent hydrocarbon group is bonded to a silicon atom. Such a siloxane unit is preferably a trimethylsiloxane unit. A dimethylphenylsiloxane unit or a compound not containing a vinyl group such as a methyldiphenylsiloxane unit; and preferably a dimethylvinylsiloxane unit or a compound containing a vinyl group such as a methylphenylvinylsiloxane unit. Alkoxy groups such as methoxy and ethoxy may be present.

The second component polyorganohydrogensiloxane used in the present invention functions as a crosslinking agent for the first component by causing an addition reaction of the hydrosilyl group contained in the molecule to the vinyl group in the first component. In order to form a cured product having a network structure, each molecule has an average of more than two hydrogen atoms bonded to silicon atoms in one molecule, and has at least one hydrogen atom at the terminal.

Examples of the organic group bonded to the silicon atom of the siloxane unit include those equivalent to the organic groups other than the vinyl group in the above-mentioned first component. A methyl group is most preferred in view of the compatibility of one component.

The siloxane skeleton of the second component is linear and the viscosity is not particularly limited, but is preferably from 10 to 200 cp because it is easy to synthesize and does not volatilize during storage or when the oxidation reaction is performed by heating. .

Specific examples of the second component include a unit having a hydrosilyl group at the molecular terminal such as a dimethylhydrogensiloxane unit and a linear polyorganohydrogensiloxane having at least one in the molecule.

In the present invention, the polyorganosiloxane composition used for forming the adhesive layer contains the above-mentioned first component and second component.

In the composition, the ratio of the vinyl groups in the first component to the hydrogen atoms bonded to the silicon atoms in the second component can vary considerably, for example, from one hydrogen group to one vinyl group. The number can be set in the range of 0.1 to 100.

The amount of the second component relative to the first component depends on the vinyl group content of the first component and the hydrosilyl group content of the second component, but the amount of the second component is 100 parts by weight of the first component. Is usually 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight.

When the amount of the second component exceeds 50 parts by weight, sufficient physical properties cannot be imparted to the adhesive layer.

The polyorganosiloxane composition used in the present invention contains the above-mentioned first component and second component. If necessary, a filler, an adhesion-imparting agent, a heat-resistance improving agent, a flame retardant Agents and the like can be blended.

In this system, since a curing reaction catalyst is separately stored, it is not necessary to particularly add a curing inhibitor. However, when this is used, the development of adhesiveness may be hindered. Cost.

The filler is used to impart appropriate plasticity and workability to the polyorganosiloxane composition, and to provide necessary mechanical properties to the cured adhesive layer. Can be contained.

In order to obtain an adhesive having good workability, at least a part of the filler is preferably a silica-based filler having a particle diameter of 20 μm or less. Examples of the reinforcing filler include fumed silica, silica aerogel, and silica fine powder such as precipitated silica, which may be used as it is or may be treated with an organosilicon compound to make the surface hydrophobic. .

Examples of the organosilicon compound used for the surface treatment include dimethyldichlorosilane, trimethylchlorosilane, hexamethyldisilazane, octamethylcyclotetrasiloxane, and the like. Disilazane is particularly preferred.

In the treatment, the organosilicon compound used for the treatment is adsorbed on the surface of the silica fine powder at room temperature or at a high temperature in a gas phase or a liquid phase using an inert solvent such as n-hexane, and then heat-treated. It can be carried out by organosilylating silanol groups on the surface of the fine powder. Further, in the step of kneading the reinforcing filler with the first component, the treatment may be carried out by kneading with heat with an organosilicon compound such as hexamethyldisilazane.

Examples of the non-reinforcing filler include silica such as diatomaceous earth and ground quartz, titanium oxide, alumina, magnesium oxide, zinc oxide, calcium carbonate, carbon black and the like.

The amount of the filler is not particularly limited, but is preferably 5 to 500 parts by weight, more preferably 10 to 400 parts by weight, per 100 parts by weight of the first component.

If the amount is less than 5 parts by weight, sufficient mechanical performance cannot be obtained. If the amount exceeds 500 parts by weight, not only the viscosity becomes high but also the cured adhesive layer cannot have rubber elasticity.

Examples of the adhesion-imparting agent include epoxy groups such as 3-glycidoxypropyl, 2- (3,4-epoxycyclohexyl) ethyl, vinyl, 3-methacryloxypropyl, and 3-acryloxypropyl, or olefinic difunctional groups. A substituted or unsubstituted alkoxy group such as methoxy, ethoxy, or 2-methoxyethoxy having at least one carbon functional group selected from groups having a heavy bond and bonded to a silicon atom is used.

As another adhesiveness-imparting agent, a silicon-functional isocyanurate having a substituted or unsubstituted alkoxy group such as methoxy, ethoxy, propoxy or 2-methoxyethoxy bonded to a silicon atom is also used.

As such an adhesion-imparting agent, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyl (methyl) dimethoxysilane, 2- (3,3 4-epoxycyclohexyl) ethyltrimethoxysilane, 2-
Epoxy group-containing silanes such as (3,4-epoxycyclohexyl) ethyltriethoxysilane and 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane and their partially hydrolyzed condensates; 3-methacryloxypropyl (Meth) such as trimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyl (methyl) dimethoxysilane
Acrylic group-containing silanes and their partially hydrolyzed condensates; vinyl-containing silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane and their partially hydrolyzed condensates; 3-glycidoxy Examples thereof include linear siloxanes such as methylsiloxane containing a group and a 2- (trimethoxysilyl) ethyl group; and cyanuric ring-containing organosilicon compounds such as tris (3-trimethoxysilylpropyl) isocyanurate.

Next, when used for bonding, the thickness of the adhesive should be 1
0 mm or less is preferable, and 0.01 to 5 mm is more preferable. If the thickness exceeds 10 mm, the curing at the center may be insufficient.

The kneading and preforming can be carried out at room temperature, and if necessary, may be carried out by heating to a temperature of, for example, 50 to 200 ° C.

Next, a cured silicone rubber containing a platinum catalyst will be described.

The platinum content of the cured silicone rubber containing a platinum-based catalyst is 0.1 to 1000 ppm, preferably 1 to 20 ppm.
It is 0 ppm. If the amount is less than 0.1 ppm, the curing of the adhesive putty will not proceed, and if it exceeds 1000 ppm, not only will there be no effect of meeting the compounding amount, but it is economically disadvantageous.

The platinum catalyst is chloroplatinic acid, a complex mixture obtained by heating chloroplatinic acid and alcohol, a platinum compound such as platinum-olefin complex, platinum-vinylsiloxane complex, platinum-triphenylphosphine complex, palladium.
-Palladium compound such as phosphine complex, rhodium-
Examples thereof include those in which platinum or palladium is supported on a support such as a rhodium compound such as a phosphine complex, alumina, silica, or carbon.

The curing method of a silicone cured product containing a platinum-based catalyst is most preferably an addition curing type, but the effect is also exhibited in an organic peroxide curing type.

Further, a method for bonding to a cured silicone rubber using this adhesive will be described.

An example of an integrated keyboard top for a personal computer will be described as an example of a cured silicone rubber.

First, the viscosity at 25 ° C. of which both ends were blocked with a dimethylvinylsilyl group was 1,000,
Dimethylsiloxane polymer 100 of 000 cp
Part, fumed silica 4 having a specific surface area of 300 cm ² / g
0 parts, 8 parts of hexamethyldisilazane and 1 part of water were charged into a kneader, stirred at room temperature for 1 hour, heated to 150 ° C., and kept at room temperature for 2 hours. Thereafter, the mixture was cooled to room temperature, and 20 parts of a dimethylsiloxane polymer having a viscosity of 10,000 cp at 25 ° C. capped at both ends with dimethylvinylsilyl groups was further added to the mixture.
3 parts of methyl hydrogen polysiloxane having a viscosity of 10 cp at 5 ° C., 4 parts of vinyl methyl polysiloxane having a viscosity of 1000 cp at 25 ° C. containing 5 mol% of a vinyl group directly bonded to a silicon atom, and curing at room temperature 0.1 parts of acetylene alcohol to extend the time until 100 ppm of platinum-vinylsiloxane complex
Add and mix well until uniform.

The obtained uncured silicone rubber composition was put into a mold, press-vulcanized at a temperature of 170 ° C. and a pressure of 100 kg / cm ² for 10 minutes, and then demolded, followed by 4 hours in an oven at 200 ° C. 280m in length
m, a width of 100 mm, a height of 10 mm, and a thickness of 2 mm were molded into a silicone rubber keyboard.

Next, a 200 μm thick piece of the integrally molded keyboard top as a cured silicone rubber obtained as described above was applied to the top.
A method for curing and bonding the thick adhesive will be described. FIGS. 1 and 2 are vertical sectional views of an integrally molded keyboard top 1 for carrying out the bonding method of the present invention, and FIG. 3 is a flowchart showing the procedure of the bonding method of the present invention.

Now, this integrally molded keyboard top 1
The above-mentioned film-like adhesive 2 is arranged on the surface 1A (step 1 in FIG. 1).

Next, the keyboard top 1 on which the adhesive 2 is disposed is left at room temperature (25 ° C.) for 12 hours (FIG. 2).
/ Step 2), the adhesive is cured and adhered to the keyboard top.

The laminate thus obtained is composed of a keyboard top 1 as a cured silicone rubber and an adhesive 2
Have a two-layer structure in which they are directly adjacent to each other, and there is no intermediate layer such as an adhesive layer.

As described in detail above, according to the bonding method of the present invention, a silicone rubber cured product containing a platinum-based catalyst has, as a first component, a vinyl group bonded to a silicon atom in a molecule. Substantially linear, having a viscosity of 10-8,
2,000,000 cp polyorganosiloxane; and as a second component, a polyorganohydrogensiloxane characterized in that the molecule has at least one hydrogen atom bonded to silicon atoms on the terminal at an average of more than two atoms. An adhesive comprising a polyorganosiloxane composition having a viscosity of 10 to 8,000,000 cp is disposed, and then the cured silicone rubber and the adhesive are cured and adhered. Directly bonded.

This is presumably because the platinum component in the cured silicone material acted on the adhesive putty side to bring out the adhesive action.

The present invention is not limited to the scope of the above embodiment. For example, in the above-described embodiment, an adhesive is disposed on the silicone rubber to form a two-layer structure in which the cured silicone rubber and the adhesive are adhered. However, the adhesive is formed from the cured silicone rubber and glass, plastic, metal, or wood. It is also possible to adhere the adherend to the cured silicone rubber by sandwiching it between adherends such as carbon or the like and then heating to room temperature or an appropriate temperature.

In this case, a silicone cured product, an adhesive,
Then, a laminate having a three-layer structure of the adherend is formed.

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described.

A millable silicone rubber composition was prepared at the following ratio, and the silicone rubber composition was cured. Millable silicone rubber 100 parts by weight Additional curing agent A agent 0.5 parts by weight Additional curing agent B agent 2.0 parts by weight The cured product is placed in a mold cavity of 80 mm long × 25 mm wide × 2 mm thick, After pressing under a condition of 170 ° C. × 10 minutes and demolding, the resultant was cured by heating in a 200 ° C. oven for 4 hours to obtain a millable silicone rubber specimen. The platinum content of the test specimen after blending is 85 ppm
Met.

On the other hand, the adhesive composition was compounded by the following method.

Both ends are blocked with a dimethylvinylsilyl group, and a specific surface area of 300 m ² / g is added to 100 parts by weight of a polydiorganosiloxane having a viscosity of 60,000 cp and comprising 99.8 mol% of dimethylsiloxane units and 0.2 mol% of methylvinylsiloxane units. 60 parts by weight of fumed silica, 12 parts by weight of hexamethyldisilazane, and 6 parts by weight of water were mixed and kneaded at room temperature for 1 hour with a universal kneader to raise the temperature to 150 ° C. after trimethylsilylation of the silica surface. And further kneaded for 2 hours to remove the generated decomposition residue.

Thereafter, the temperature was lowered to room temperature, and 3 parts by weight of a polyhydrogensiloxane having a viscosity of 50 cp and comprising a methylhydrogensiloxane unit having one hydrogen atom at each end and 5 mol% of a hydrogen group in a side chain were blended. The mixture was kneaded to obtain an adhesive.

An adhesive having a length of 20 mm
× 25 mm in width × 0.4 mm in thickness, and two test pieces were stuck together to prepare a test piece for a shear tensile test.

FIG. 4 is a sectional view of the completed test piece.

When left in an environment of 25 ° C. for 12 hours,
The adhesive was cured and adhered to the specimen.

A shear tensile test was performed on the test piece on which the bonding was completed. The shear tensile test was performed at a tensile speed of 10 mm / min using an Autograph AG1000D manufactured by Shimadzu Corporation. As a result, the test piece was broken. The tensile strength at break was 5 MPa.

(Comparative Example 1) Hereinafter, Comparative Example 1 of the present invention will be described.

A millable silicone rubber composition was prepared at the following ratio, and the silicone rubber composition was cured. Millable silicone rubber I 100 parts by weight Additive curing agent A agent 0.5 parts by weight Additive curing agent B agent 2.0 parts by weight The platinum content of I after blending was 85 ppm.

The above cured product is 80 mm long × 25 mm wide ×
Place in a mold cavity of 2mm thickness, 170 ℃ × 1
After pressing under the condition of 0 minutes and removing the mold, the composition was heated and cured in an oven at 200 ° C. for 4 hours to obtain a millable silicone rubber specimen in the same manner as in Example 1.

The platinum content of the cured specimen was 85 ppm.
Met.

On the other hand, an adhesive composition was compounded by the following method.

A fume having a specific surface area of 300 m ² / g was added to 100 parts by weight of a polydiorganosiloxane having both ends capped with a dimethylvinylsilyl group and having a viscosity of 60000 cp and comprising 99.8 mol% of dimethylsiloxane units and 0.2 mol% of methylvinylsiloxane units. 60 parts by weight of porous silica, 12 parts by weight of hexamethyldisilazane, and 6 parts by weight of water were mixed and kneaded at room temperature for 1 hour with a universal kneader to trimethylsilylate the silica surface.
And further kneaded for 2 hours to remove generated decomposition residues.

Then, the temperature was lowered to room temperature, and 3 parts by weight of a polyhydrogensiloxane having a viscosity of 50 cp and comprising methylhydrogensiloxane units having 5 mol% of hydrogen groups in the side chains other than the terminals were blended and kneaded. , Adhesive was obtained.

When left in an environment of 25 ° C. for 12 hours,
The adhesive was cured, but the specimen peeled.

Embodiment 2 Hereinafter, Embodiment 2 of the present invention will be described.

The addition-curable liquid silicone rubber (LIM) for injection molding was cured by the following method. Addition-curable liquid silicone rubber for injection molding (agent A) 50 parts by weight Addition-curable liquid silicone rubber for injection molding (agent B) 50 parts by weight After mixing LIM (agent A) and (agent B) 1: 1, A keyboard was molded at 170 ° C. for 3 minutes using an injection molding machine manufactured by Aburg.

A platinum-based catalyst was blended in LIM (agent A). The platinum content of the finished molded product was found to be 100 ppm.

On the other hand, 1 part by weight of 3-methacryloxypropyltrimethoxysilane was further blended with the adhesive blended in Example 1 to obtain an adhesive.

Using the above composition, 8 mm long × 5 mm wide
× An adhesive was applied to a shape having a thickness of 0.2 mm, the adhesive was placed on the keyboard top surface, a PET film having a thickness of 0.1 mm cut into an appropriate size was further placed thereon, and pressed. .

FIG. 5 is a vertical sectional view showing a state in which a PET film is adhered to a keyboard top via an adhesive.

When left for 12 hours in an environment of room temperature (25 ° C.) × relative humidity (60%), the adhesive was cured,
It was firmly adhered to the film and LIM.

Comparative Example 2 Hereinafter, Comparative Example 2 of the present invention will be described.

An addition-curable liquid silicone rubber (LIM) composition for injection molding was prepared by the following method, and the silicone rubber composition was cured. Addition-curable liquid silicone rubber for injection molding (agent A) 50 parts by weight Addition-curable liquid silicone rubber for injection molding (agent B) 50 parts by weight After mixing LIM (agent A) and (agent B) 1: 1, A keyboard was molded at 170 ° C. for 3 minutes using an injection molding machine manufactured by Aburg.

A platinum-based catalyst was blended in LIM (Agent A). The platinum content of the finished molded product was 100 ppm.

A one-component condensation-curable alcohol-type silicone sealant is applied to the keyboard top surface,
Further, it was cut into an appropriate size, a PET film having a thickness of 0.1 mm was placed thereon, and pressure-bonded, and left for 3 days in an atmosphere of room temperature (25 ° C.) × relative humidity (60%).

When the adhesion of the test piece after standing was confirmed, the PET film and the one-component condensation-curable alcohol-type silicone sealant were adhered.
The component condensation-curable alcohol-type silicone sealant was peeled off.

(Embodiment 3) Embodiment 3 of the present invention will be described below.

The addition-curable liquid silicone rubber (LIM) composition for injection molding was prepared by the following method, and the silicone rubber composition was cured. Addition-curable liquid silicone rubber for injection molding (agent A) 50 parts by weight Addition-curable liquid silicone rubber for injection molding (agent B) 50 parts by weight After mixing LIM (agent A) and (agent B) 1: 1, A keyboard was molded at 170 ° C. for 3 minutes using an injection molding machine manufactured by Aburg.

A platinum-based catalyst was blended in LIM (agent A). The platinum content of the finished molded product was 100 ppm.

On the other hand, 1 part by weight of 3-methacryloxypropyltrimethoxysilane was further blended with the adhesive blended in Example 1 to obtain an adhesive.

Using the above composition, length 8 mm × width 5 mm
An adhesive was applied to a shape having a thickness of 0.2 mm, the adhesive was placed on the top surface of the keyboard, and a 0.1 mm-thick polycarbonate film cut to an appropriate size was placed thereon and pressed.

When left in an oven at 80 ° C. for 30 minutes, the adhesive was cured, and the polycarbonate film and L
Strongly adhered to IM.

Comparative Example 3 Hereinafter, Comparative Example 3 of the present invention will be described.

An addition-curable liquid silicone rubber (LIM) composition for injection molding was prepared by the following method, and the silicone rubber composition was cured. Addition-curable liquid silicone rubber for injection molding (agent A) 50 parts by weight Addition-curable liquid silicone rubber for injection molding (agent B) 50 parts by weight After mixing LIM (agent A) and (agent B) 1: 1, A keyboard was molded at 170 ° C. for 3 minutes using an injection molding machine manufactured by Aburg.

A platinum-based catalyst was blended in LIM (Agent A). The platinum content of the finished molded product was 100 ppm.

A one-component addition-curable silicone adhesive (RTV) is applied to the keyboard top surface by 8 mm long × 5 mm wide.
× Apply under the condition of thickness 0.2 mm, further cut to an appropriate size, place a 0.1 mm-thick polycarbonate film and crimp it,
Left for hours.

When the adhesion state of the test piece after removal was confirmed, no curing of the RTV was confirmed.

Therefore, in an oven at 130 ° C.,
When left for 0 minutes, curing of the RTV was confirmed,
As a result, the polycarbonate film was partially peeled off from the LIM, and the polycarbonate film was thermally melted.

[0103]

According to the present invention, an adherend can be successfully adhered to a cured silicone rubber.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of an integrally molded keyboard top for performing the bonding method of the present invention.

FIG. 2 is a vertical sectional view of an integrally molded keyboard top for performing the bonding method of the present invention.

FIG. 3 is a flowchart illustrating a procedure of the bonding method of the present invention.

FIG. 4 is a sectional view of a test piece for a shear tensile test.

FIG. 5 is a vertical sectional view showing a state in which a PET film is adhered to a keyboard top via an adhesive.

[Explanation of symbols]

1 ... key board top (cured silicone rubber), 2
……adhesive.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09J 183/05 C09J 183/05 F-term (Reference) 4F100 AA37C AB01C AB24A AG00C AK01C AK11B AK11G AK52A AK52B AK52G AL05B AP00C BA02 BA03 BA07 BA10A BA10C EJ08 EJ08A EJ082 EJ17 EJ172 GB08 GB33 GB41 JA06B JL08A YY00A YY00B 4J035 CA02U CA14U GA01 HA01 HB03 4J040 EK042 EK091 GA01 GA05 GA07 HA096 HD41 HD43 KA14 LA05 MA05 MA08

Claims (10)

[Claims] 1. A substantially linear, viscosity having a vinyl group bonded to a silicon atom in a molecule as a first component on a surface of a first layer made of a cured silicone material containing a platinum-based catalyst. An adhesive composition comprising a polyorganosiloxane having a thickness of 0 to 8,000,000 cp and a polyorganohydrogensiloxane having a hydrogen atom bonded to an average of more than two silicon atoms in the molecule as a second component has a thickness of 0%. Step of forming a second layer by applying a thickness of 0.001 to 20 mm, and leaving it in an environment of 20 ° C to 30 ° C or heating it to 30 ° C or more to bond the first layer while curing the second layer. And a bonding method comprising: 2. The bonding method according to claim 1, wherein the first component has two or more vinyl groups bonded to a silicon atom in one molecule. 3. The bonding method according to claim 1, wherein the second component has at least one hydrogen atom bonded to a silicon atom at a terminal. 4. The bonding method according to claim 1, wherein the content of the platinum-based catalyst contained in the cured silicone rubber is 0.1 to 1,000 ppm. Bonding method. 5. A substantially linear, viscosity of 10%, having, as a first component, a vinyl group bonded to a silicon atom in a molecule on the surface of a first layer made of a cured silicone material containing a platinum-based catalyst. An adhesive composition comprising a polyorganosiloxane having a thickness of 0 to 8,000,000 cp and a polyorganohydrogensiloxane having a hydrogen atom bonded to an average of more than two silicon atoms in the molecule as a second component has a thickness of 0%. Forming a second layer by applying a thickness of 0.001 to 20 mm; and a third layer formed of a material selected from the group consisting of glass, plastic, metal, wood, and carbon on the second layer. And a step of leaving the substrate in an environment of 20 ° C. to 30 ° C. or heating it to 30 ° C. or higher to cure the second layer and bond the second layer to the first layer. 6. A substantially straight-chain, viscosity having a vinyl group bonded to a silicon atom in a molecule as a first component on a surface of a first layer made of a silicone cured product containing a platinum-based catalyst. An adhesive cured product comprising a polyorganosiloxane of ~ 8,000,000 cp and a polyorganohydrogensiloxane having, as a second component, more than two hydrogen atoms bonded to silicon atoms on average in the molecule. A silicone rubber molded article comprising a second layer having a thickness of 0.001 to 20 mm. 7. The silicone rubber molded article according to claim 6, wherein the first component has two or more vinyl groups bonded to a silicon atom in one molecule. 8. The silicone rubber molded article according to claim 6, wherein the second component has at least one hydrogen atom bonded to a silicon atom at a terminal. 9. The bonding method according to claim 6, 7 or 8, wherein the content of the platinum-based catalyst contained in the cured silicone rubber is 0.1 to 1,000 ppm. Bonding method. 10. A substantially straight-chain, first component having a vinyl group bonded to a silicon atom in a molecule on the surface of a first layer made of a cured silicone material containing a platinum-based catalyst.
An adhesive cured product containing a polyorganosiloxane having a viscosity of 10 to 8,000,000 cp, and a polyorganohydrogensiloxane having, as a second component, a hydrogen atom bonded to an average of more than two silicon atoms in the molecule. A second layer, applied to a thickness of 0.001 to 20 mm, glass,
A silicone rubber molded article formed of a material selected from the group consisting of plastic, metal, wood, and carbon, and having a third layer laminated on the second layer.